


You Plus Me

by Irhaboggles



Category: Supergirl (TV 2015)
Genre: Alex Danvers & Lena Luthor Friendship, Bisexual Kara Danvers, Comedy, Cute, Endgame Kara Danvers/Lena Luthor, Established Kara Danvers/Lena Luthor, F/F, Family, Flirting, Flirty, Fluff, Friendship, Funny, Gay, Humor, Jokes, Lesbian, Lesbian Lena Luthor, Math, One Shot, Romance, Samantha "Sam" Arias & Lena Luthor Friendship, Season 3, Sequel, Ship, Short, Smart Ruby Arias, SuperCorp, flirt, post season, puns, queer
Language: English
Status: Completed
Published: 2020-12-10
Updated: 2020-12-10
Packaged: 2021-03-10 05:28:59
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,107
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27989256
Author URL: https://archiveofourown.org/users/Irhaboggles/pseuds/Irhaboggles
Summary: Kara, Lena and Alex tutor Ruby in math while Sam makes them all dinner. Or at least, they TRY to tutor Ruby. But with Kara constantly dropping math-related flirtations and Lena falling for all of them, it's all Alex and Sam can do to try to keep them on track. But Ruby, of course, doesn't mind taking a homework break at all.
Relationships: Kara Danvers/Lena Luthor
Comments: 15
Kudos: 238





	You Plus Me

**Author's Note:**

  * For [Snorlax891](https://archiveofourown.org/users/Snorlax891/gifts).



"And then you take the number on top and cross-multiply it with the number on the bottom," Lena explained, dragging her finger across Ruby's homework. She, Kara and Alex had all taken up the _enormous_ task of trying to help the younger girl with her homework. Sam was also home, but she was busy making dinner.

"Ok, so… Like this?" Ruby asked, tapping her pencil on each of the two numbers Lena had pointed to before quickly calculating the answer.

"Yes! Exactly!" Lena sounded genuinely proud and Ruby gave her a bashful smile.

"Way to go, kiddo, you're getting good at this!" Alex agreed, patting the girl on the back, and Kara also gave her a thumbs up of approval.

"Well, thank you guys for helping me," Ruby was as red as her name at this point, looking shyly down at her papers. As bright as she was, she still struggled with schoolwork from time to time, so she felt incredibly lucky that she should have three super intelligent and super sweet women at her disposal to help her try to find new ways to learn the things she didn't already understand.

And Sam was equally grateful. Usually, she was Ruby's tutor. But with Kara, Alex and Lena all visiting for dinner, that gave Sam time to actually prep a really good meal while they helped Ruby through her homework. Or, at least, that's how it _started_. But what the three women, plus Ruby, all had in common was a very silly and immature sense of humor. As such, it didn't take too long for all of it to devolve into a fit of giggles.

"Top cross multiplying with the bottom, eh Lena?" Kara snickered softly at the Luthor.

"Kara!" Lena whispered back with an indignant tone and expression. She gently slapped Kara's hand, which only made Kara laugh a little louder.

"Tell me more about cross-multiplying, and what it takes to be a top or bottom," she whispered.

"Kara!" Lena repeated. Now it was her turn to match Ruby's name. Alex, meanwhile, shot an unamused glare at both of them before clearing her throat and attempting to steer them all back on topic.

"Ruby!" she said loudly, hoping that the child hadn't heard any of Kara and Lena's immature antics. "What's the next question?"

"Well, this one talks about multiplying decimals by fractions. I think I know what to do here though…" she began slowly.

"Oh?" Alex gestured for her to explain.

"Well, a decimal is just a fraction of 100, so I'd just try to make the actual fraction a multiple of 100, right?" she asked.

"Exactly!" both Lena and Alex's eyes lit up and they nodded enthusiastically.

"Oh, and it looks like you're multiplying a six and a nine together…" Kara leaned over Lena to sneak a peak at Ruby's paper.

"Kara!" for a third time, Lena whisper-snapped at Kara, but once again, Kara only gave her a charming smile in return.

"Speaking of numbers, I guess I'd say you're a nine," she whispered to Lena.

"Only a nine?" despite trying to get Kara to behave around Ruby, Lena couldn't help but take Kara's bait with some level of indignation.

"Yes, because I'm a seven," Kara replied.

"Oh, Kara, you're not a seven," Lena's face instantly softened and she reached out to touch Kara's hand, as if trying to reassure the woman away from her self-deprecating remark. But then a mischievous look entered Kara's eyes…

"And you know how the old joke goes, right? Seven ate nine," then she shot Lena a very big wink before nudging her.

"Oh my god, Kara," Lena pulled her hand away from Kara's and buried her face in it.

Ruby, meanwhile, had since begun to snicker under her breath. Although she'd politely tried to ignore Kara's flirtations with Lena earlier, she couldn't deny that Kara had some very funny one-liners.

"Next question!" Alex suddenly interrupted. The moment she heard Ruby laugh, she jumped into overprotective mode and shot another glare towards the blushing Lena and smirking Kara. The second Ruby lowered her head to read the next question, Alex mouthed a warning.

_Shut up! Or else!_

_Or else what?_ Kara mouthed back, with an incredibly disbelieving face.

 _She's a child!_ Alex mouthed with a look of anger and disbelief, gesturing to Ruby and her rather simplistic homework. Even though she found it challenging, it was the kind of math Kara, Lena and Alex had aced years and years ago.

 _Kid's gotta learn somehow!_ Kara mouthed back with an innocent shrug.

"Kara!" Alex actually spoke aloud that time, hissing and narrowing her eyes disapprovingly.

 _We're her tutors!_ Kara mouthed for a final time. The implication she didn't speak, but which still hung clearly in the air, was this: _Sam just never said what we were tutoring her for!_

"This isn't biology, Kara," Alex spoke through grit teeth.

"Speaking of tutors! You know what rhymes with it?" Kara asked suddenly, turning her attention to Lena again and giving her a sly glare.

"Oh my god, Kara," the Luthor repeated in dismay. Ruby's shoulders shook with silent laughter. She wasn't focusing on her paper at all, she was focusing on not giving away the fact that she was having the time of her life listening to one of her "gay aunts" trying to seduce the other one while the third watched in annoyance and dismay. Although Ruby appreciated Alex's attempt to shield her, it wasn't necessary. Ruby wasn't stupid. She also went to a public middle school. She knew _all_ about all that "icky adult stuff" already.

Sam, meanwhile, winced. Because she was in the kitchen, she was missing more than Alex and Ruby were, but she could still hear the occasional shriek or shrill giggle from either Kara or Lena. And she occasionally heard snippets of Kara's suggestive remarks. As such, it wasn't very hard for her to figure out what was going on. And given all that she knew about Lena and Kara (both as individuals and a couple) it did not surprise her in the slightest. It did make her mildly uncomfortable, for Ruby's sake, but fearing she would make it worse if she tried to intervene, she did her best to keep on cooking. She trusted Lena not to let things get too raunchy, so that would have to be enough… For now… Hopefully…

"I can't wait until we reach integration," Kara continued suggestively.

"That won't be until a few years from now when she's in calculus," Alex deadpanned louder.

"Don't be so obtuse, Alex," Kara shot back with a shrug. "Lena is a cute angle, errr, _angel_ and I need her to know that."

"Now dear, we don't want to cause any division amongst the group right now, ok?" Lena asked lightly, torn between amusement and mortification and struggling not to just burst out laughing from the sheer silliness and awkwardness of it all.

"Hey, this isn't complex or imaginary," Kara continued to speak with a relaxed, aloof tone, dropping bad pun after bad pun. "The only sort of math I'm interested in is Me + You," she finished, becoming bold enough to finish by kissing Lena on the cheek.

As one may have expected, while Lena gave a little surprised shriek of embarrassment and delight, Kara looked quite pleased with herself. At the same time, Alex facepalmed and Ruby burst out into a fit of giggles, no longer able to keep her laughter at bay. Sam still stood in the kitchen, exhaling slowly in order to calm her nerves and fight the urge to turn around.

"Don't look, don't look, don't look," she muttered to herself. "Everything is fine, and it doesn't matter at all…"

"Things will only get exponentially better after this," Kara promised with a saucy little wink.

"We're going to expand our brains and fill our minds with learning and math!" Ruby agreed. Kara looked absolutely delighted by this reply and she raised a fist for a fist bump, which Ruby was more than happy to return.

"You're a bad influence, you know that?" Alex demanded, crossing her arms and glaring disapprovingly at Kara.

"I learned from the best!" Kara replied sweetly.

"Oh, burn!" because she was no longer trying to hide her amusement, Ruby had no issue in playfully joining in the Alex teasing session.

"I thought this was supposed to be a math tutoring session!" the elder Danvers complained, glaring as she watched Ruby rise up against her.

"This is more fun though!" Ruby laughed.

"But it's also not what's going to be graded tomorrow morning in class!" Sam finally said over her shoulder. Ruby winced.

"Ah, right… Ok… I guess," her embarrassment turned into a tired, reluctant sigh as she slouched back down in her seat.

"Ah! Yes! Where did we leave off again?" Lena was quick to take the easy out Sam had provided for her.

"Well, we were-" Kara began seductively.

"Can someone who isn't Kara answer that?" Lena cut her off, intentionally looking at Alex and Ruby.

"Ouch. I am _hurt_ ," Kara put a hand to her chest.

"You didn't raise your hand," Alex stuck her tongue out triumphantly.

" _You're_ acting more like a middle school student than I am," Kara scoffed, gesturing to Alex's stuck out tongue.

"Hey! I don't do that!" Ruby looked up at Kara indignantly.

"Oh, and I guess she's back on my side!" Alex sounded far too satisfied with herself, slouching back in her seat and crossing her arms smugly.

"Well, the only _side_ I need is Lena's back-"

"Oh, now you're dealing with improper fractions that aren't easily divided into decimals or smaller fractions!" Lena interrupted loudly.

"Oooh yeah, that's some _hard_ stuff right there, isn't it?" Kara asked, but she was unable to stop from bursting into a fit of giggles by the end of her attempt at a seductive-sounding pickup line.

"I wonder if I could… plug this into my calculator," Ruby agreed with a wink. Kara smiled at her, but before she could speak, they all heard Sam clear her throat from the kitchen again. Ruby pouted at her, even though she didn't see it because Sam's back was still turned to them.

"Anyway, it looks like I have 39/17," she read loudly.

"Thank you," Sam replied.

"Well, the only number I'm interested in is Lena's," Kara smirked, winking at the Luthor.

"And the only one I'm interested in is the one I'm about to dial," Alex replied, holding up her phone with a "911" on the screen.

"Pfft, you're going to have me _arrested_?" Kara snorted. Of course, the overarching humor was the idea that Alex would somehow arrest Kara for anything, but the underlying humor was that Kara was Supergirl. They both knew the odds of her getting into legal trouble were almost zero.

"Besides, aren't _you_ an officer already?" Ruby reminded Alex playfully.

"I'm calling in backup," Alex answered without missing a beat, still looking very unamused. "Someone needs to restrain that madwoman."

"What can I say? I'm _madly_ in love!" Kara pretended to swoon into Lena's arms, but because Lena wasn't even facing her direction, it just led to Kara awkwardly falling over onto Lena's shoulder.

"You don't say?" Lena muttered, feeling squished as Kara almost pushed her over into Ruby, which earned another laugh from Ruby and another exasperated sight from Alex. This was the last time she let Kara and/or Lena be Ruby's tutors… in _anything_.

This really had been a bad idea from the start, Alex had tried to tell Sam. But sweet, optimistic Sam hadn't realized just how bad Kara could be. But now she knew. And while she continued to cook dinner, still torn between amusement and exasperation herself, Ruby and her three unofficial gay aunts continued to work on math. And by "work on math", that meant listening to Kara's insufferable puns rather than focusing on Ruby's problems, while Lena could do little more than swoon and occasionally try to help, leaving Alex to try to keep them all focused… ish…

But if anyone had asked Ruby, Kara's math lessons were infinitely more enjoyable than anything her own schoolteacher could've cooked up. It was the first night she'd ever enjoyed doing homework, even if it took longer than necessary because of all the… tangents they went off on. But despite how little focus any of them showed for the homework when compared to Kara's antics, it really was nice just to have the family all back together again! It was like Kara had said, the most important and interesting equation of all was simply "You + Me".

**Author's Note:**

> AN: Inspired by the wonderful and hilariously lewd Snorlax891! Set post-S3, after Reign was banished. And in this one, Kara and Lena ARE a couple (and become one sometime during S3).


End file.
